Nanshiungosaurus
Nanshiungosaurus is a genus of therizinosaurian theropod dinosaur from the Cretaceous of China. Two species have been named in the genus: the type species Nanshiungosaurus brevispinus and Nanshiungosaurus bohlini. Discovery and naming In 1979 Nanshiungosaurus brevispinus was named and described by Dong Zhiming. The generic name refers to Nanxiong. The specific name is derived from Latin brevis, "short", and spina, "thorn", in reference to the short vertebral spines. The holotype specimen, IVPP V4731, was near Dapingcun in Guangdong found in a layer of the Yuanpu Formation, dating from the Late Cretaceous Campanian. It consists of a partial skeleton lacking the skull but including eleven cervical, ten dorsal and six sacral vertebrae, and a bulky pelvis. It was first thought to be a small, strange sauropod characterised by a shorter but thicker neck than other sauropods.Z. Dong, 1979, Cretaceous dinosaurs of Hunan, China. Mesozoic and Cenozoic Red Beds of South China: Selected Papers from the "Cretaceous-Tertiary Workshop", Institute of Vertebrate Paleontology and Paleoanthropology & Nanjing Institute of Paleontology (eds.), Science Press, Nanxiong, China pp. 342-350 In 1997 Dong and You Hailu named and described a second species: Nanshiungosaurus bohlini, based on a skeleton found in 1992 near Mazongshan. The specific name honours the Swedish paleontologist Birger Bohlin. The holotype is IVPP V 11116, from the Early Cretaceous Upper Xinminbao Group dating from the Barremian-Aptian. It consists of only eleven cervical and five dorsal vertebrae with some ribs.Dong Z. and Yu H., 1997, "A new segnosaur from Mazongshan Area, Gansu Province, China", In: Dong (ed). Sino-Japanese Silk Road Dinosaur Expedition. China Ocean Press, Beijing. pp. 90-95 Dong and You presented no evidence or argumentation supporting the assignment of the species to Nanshiungosaurus. In view of the lack of synapomorphies, shared unique traits, and the large age difference with Nanshiungosaurus brevispinus it is generally considered that the second species might warrant its own genus.Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 158 Description Gregory S. Paul in 2010 estimated the length of Nanshiungosaurus brevispinus at five metres, the weight at six hundred kilogrammes.Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 160 The species distinguishes itself by the possession of twelve cervical vertebrae. The number of sacral vertebrae was first determined at five, later corrected to six.Zanno, L.E., 2008, A taxonomic and phylogenetic reevaluation of Therizinosauria (Dinosauria: Theropoda): Implications for the evolution of Maniraptora, PhD Thesis, The University of Utah. pp. 329 "Nanshiungosaurus" bohlini is a larger form, estimated by Paul at six metres and 1.3 tonnes. Phylogeny Nanshiungosaurus brevispinus was in 1979 by Dong assigned to the Titanosaurinae, still based on the assumption it were a sauropod. In 1992 the species was assigned to the Segnosauridae,Z. Dong. 1992. Dinosaurian Faunas of China. China Ocean Press, Beijing pp. 188 the group today called Therizinosauridae. In 1997 however, Dong placed both species in a separate Nanshungosauridae.Z. Dong and H. Yu, 1997, "A new segnosaur from Mazongshan area, Gansu Province, China". In: Z. Dong (ed.), Sino-Japanese Silk Road Dinosaur Expedition. China Ocean Press, Beijing pp. 90-95 Cladistic analyses indicate a position for Nanshiungosaurus brevispinus that is either basal in the Therizinosauridae L.E. Zanno, D.D. Gillette, L.B. Albright and A.L. Titus, 2009, "A new North American therizinosaurid and the role of herbivory in 'predatory' dinosaur evolution", Proceedings of the Royal Society B: Biological Sciences 276(1672): 3505–3511 or just outside of that clade, basal in the Therizinosauroidea.Senter, P. (2007). "A new look at the phylogeny of Coelurosauria (Dinosauria: Theropoda)." Journal of Systematic Palaeontology, 5: 429-463 ( ). Under the definition of Therizinosauridae sensu Xu 2002, Nanshuingosaurus is by definition a therizinosaurid.X. Xu, Z.-H. Zhang, P.C. Sereno, X.-J. Zhao, X.-W. Kuang, J. Han, and L. Tan, 2002, "A new therizinosauroid (Dinosauria, Theropoda) from the Upper Cretaceous Iren Dabasu Formation of Nei Mongol", Vertebrata PalAsiatica 40(3): 228-240 Category:Dinosaurs Category:Herbivores Category:Dinosaurs of Asia Category:Cretaceous Category:Dinosaur Category:Therizinosaurs